不同肉色甘薯的营养成分与生物活性

为明确不同品种甘薯营养成分和生物活性的差异和相关性,以浙江省常见的不同肉色(紫色、橘色、黄色、白色)甘薯品种为材料,测定甘薯的营养成分含量(干物质、还原糖、可溶性糖、淀粉、可溶性蛋白、类胡萝卜素、花色苷、多酚)和生物活性清除DPPH·能力、抑制胰蛋白酶活性能力、多酚氧化酶(PPO)活性],并进行差异显著性分析、相关性分析、因子分析和聚类分析。结果表明,12个参试品种的营养成分含量均差异显著(P＜0.05)。紫肉品种甘薯的PPO活性均显著高于其他肉色品种,在清除DPPH·和抑制胰蛋白酶活性方面也显示出明显优势。相关性分析结果表明,甘薯提取液清除DPPH·能力与可溶性蛋白、花色苷和多酚含量呈极显著正相关;抑制胰蛋白酶活性能力和PPO活性除了与还原糖、可溶性糖含量无显著相关性外,与其他营养成分含量均呈显著或极显著相关。聚类分析将12个品种甘薯分为4类,分类结果与各品种在因子得分散点图上的分布情况相吻合。该研究结果可为甘薯产后利用和育种提供一定参考。

Nutritional components and bioactivities of sweet potatoes with different flesh colors

In order to define the difference and correlation of nutritional components and bioactivities of sweet potatoes with different cultivars, the content of nutritional components (dry matter, reducing sugar, soluble sugar, starch, soluble protein, carotenoids, anthocyanin and polyphenols) and bioactivities DPPH· scavenging activity, trypsin-inhibitory activity and polyphenol oxidase (PPO) activity] of sweet potatoes cultivars with different flesh colors (purple, orange, yellow and white) in Zhejiang Province were analyzed by using difference significance analysis, correlation analysis, factor analysis and cluster analysis. The results showed that there were significantly differences in the content of nutritional components in 12 cultivars (P＜0.05). The PPO activity of purple flesh cultivars was significantly higher than those of other flesh color cultivars, and showed obvious advantages in DPPH· scavenging activity and trypsin-inhibitory activity. The results of correlation analysis showed that there was an extremely significantly positive correlation between DPPH· scavenging activity and content of soluble protein, anthocyanin and polyphenols. Except for the content of reducing sugar and soluble sugar, trypsin-inhibitory activity and PPO activity were significantly correlated with the other nutritional components. The cluster analysis divided 12 cultivars of sweet potato into four categories, and the results were consistent with the distribution of each cultivar on the scatter diagram of factor score. The results could provide reference for postpartum utilization and breeding of sweet potato.